Forum Post

Mappy (Customer) asked a question.

When playing a 4k Blu ray disc, does the decoder of the ATMOS amplifier extract fixed data from 12 channels in real-time?
I see that there is already an exported WAV file for 7.1.4, is it that the content of all channels is already fixed? When playing a 4k Blu ray disc, does the decoder of the ATMOS amplifier extract fixed data from 12 channels in real-time?

  • MichalM (Dolby)

    Hello,

    There are two Dolby Formats that might be present at the Blu-Ray disc. As an elementary audio there is Dolby Digital. Second is Dolby TrueHD that might contains Dolby Atmos. Depending on the encoder settings Dolby Atmos Presentation might contain 12,14 or 16 elements. These are not channels. On the decoder side it is being rendered depending on the speaker configuration setup, to create a proper audio image and experience.
    • Mappy (Customer)

      Thank you for your answer. So is the 4k Blu ray TureHD atmos track CBI (Channel Based Immersive) or OBI (Object Based Immersive)
      • Mappy (Customer)

        Why? Can you distinguish it? Which movie do you think is CBI? Which movie is OBI?
      • Mappy (Customer)

        I feel that the Blu ray Atmos should all be OBI.
        You can see the number of dynamic objs in the potplayer.
        I watched the YouTube video and I think those are the OBJs simulated by the amplifier manufacturer using algorithms, not the object in the master file that can move parallel in many speakers in the cinema.
        What I understand is that when the master file is encoded as TureHD, many obj are merged into clusters and transformed into dynamic OBJs along with bed, including up to 1 LFE+15 dynamic OBJs.
        The last sentence agrees. The quality of a movie's sound depends on the level and diligence of the sound mixer, so sometimes the sky channel doesn't feel good
        Expand Post
      • Mappy (Customer)

        sound mixer I mean Mixing Engineer